This was a very fun game! I would love to try some more levels as this was a very good puzzle game, maybe some music could be added to spice up the atmosphere :D
I did finish all of the levels but one thing to maybe consider would be to add an arrow of some sort when you are about to throw the character in a direction. This way the player will learn how much speed and at what angle they would need to throw the characters so that they would end up where they want to be :)
Over all a very good game and everything worked fine and smoothly, keep up the good work!
I don't know if you've heard of Game Development World Championship before (gdwc2019) but it's a competition for indie game developers where they can submit their games and it's free! It's great if you want some more visibility for the game and it only takes a couple of minutes to join :)